Artificial synthetic rubber used by sole manufacturers can be divided into six categories: wear-resistant rubber, environmentally friendly rubber, air rubber, viscous rubber, hard rubber and carbon rubber.

(1) Wear-resistant rubber: Wear-resistant rubber has good wear resistance and toughness, and is very durable. This rubber material is mostly used on the sole of tennis shoes.

(2) Environmental rubber: also known as recycled rubber, this rubber outsole contains no more than 10% recycled rubber, this rubber is mainly for environmental protection.

(3) Air rubber: This means that rubber contains air, so it has a certain shock absorption function, but not very wear-resistant, not very many uses.

(4) Viscous rubber: Viscous rubber has good flexibility and is very slippery, most of which are used in indoor sports shoes.

(5) Hard rubber: The term "hard rubber" is the most comprehensive rubber in the rubber material of the outsole. It is characterized by toughness, anti-skid and wear resistance, so it is widely used.

(6) Carbonated rubber: It mainly adds carbon element to ordinary rubber material, which will make rubber more tough and wear-resistant, so running shoes are mostly made of this kind of rubber. If the back of the sole of running shoes is marked with BRS letters, it shows that the sole of running shoes is made of carbon rubber.